public class Example4_9 {
  public static void main(String args[]) {
    SIM simOne = new SIM(13889776509L);
    MobileTelephone mobile = new MobileTelephone();
    mobile.setSIM(simOne);
    System.out.println("手机号码:"+mobile.lookNumber());
    SIM simTwo = new SIM(15967563567L);
    mobile.setSIM(simTwo);	//更换SIM卡
    System.out.println("手机号码:"+mobile.lookNumber());
  }
}

